User Guide for TripSaver models including: 461-50 Cutout Mounted Reclosers, 461-50, Cutout Mounted Reclosers, Mounted Reclosers, Reclosers
Apr 7, 2025 — Understanding Sequence Coordination. TripSaver II Cutout-Mounted Reclosers with firmware version 1.8 or later are equipped with an optional.
TripSaver® II Cutout-Mounted Recloser Outdoor Distribution (15 kV and 25 kV) Sequence Coordination Application Guide Understanding Sequence Coordination TripSaver II Cutout-Mounted Reclosers with firmware version 1.8 or later are equipped with an optional Sequence Coordination Protection feature users can configure to improve service continuity. Sequence coordination decreases the number of nuisance trips of the upstream (closer to the source) device when coordinating with downstream reclosers using a combination of fast and slow curves. When the downstream recloser operates, the upstream recloser will switch (without operating) to a user-configured (usually slower) Sequence Coordination TCC curve. The upstream recloser will maintain the Sequence Coordination setting until the user-configured Coordination Reset timer expires. As an example, consider typical settings of two reclosers on a long lateral. Figure 1 shows Recloser 1 (R1) in red is the upstream recloser set with a fast curve (A) and a slow curve (C). Each time current characteristic (TCC) curve represents two operations of the recloser. The A curve is the recloser's initial trip (TCC0) and TCC1. The C curve is the recloser's TCC2 and TCC3. In Figure 2, Recloser 2 (R2) in black is the downstream recloser. It is also set with a fast (A) curve and a slow (C) curve. These curves are set so the downstream device will operate before the upstream (closer to the source) device. Current as a percent of minimum trip for the 200-A recloser Figure 1. Recloser 1's TCC curve settings. Current as a percent of minimum trip for the 200-A recloser Figure 2. Recloser 2's TCC curve settings. April 7, 2025 © S&C Electric Company 2020-2025, all rights reserved Information Bulletin 461-50 TripSaver® II Cutout-Mounted Recloser Figure 3 shows a one-line representation of the reclosers on the lateral and the two reclosers' fast and slow sequences on the same graph together. Current as a percent of minimum trip for the 200-A recloser Figure 3. Recloser 1 and Recloser 2 curve settings 2 S&C Information Bulletin 461-50 . Faulted Circuit Without Sequence Coordination When a fault happens downstream of R2, shown in Figure 4 as the dashed line, the R2's fast curve will operate twice using TCC0 and TCC1. Customers downstream of R2 will experience two operations. As the fault persists, R1's fast curve (TCC0 and TCC1) will then pick up, and customers located between R1 and R2 will also experience two reclosing operations. See Figure 5. Customers downstream of R2 will have experienced four reclosing operations. As the fault continues, the slow C curve of R2 will then pick up and operate (TCC2 and TCC3) to lockout. TripSaver® II Cutout-Mounted Recloser Current as a percent of minimum trip for the 200-A recloser Figure 4. Recloser 2's A curve operation, shown in green. Current as a percent of minimum trip for the 200-A recloser Figure 5. Recloser 1's A curve operation, shown in green . S&C Information Bulletin 461-50 3 TripSaver® II Cutout-Mounted Recloser Customers downstream of R2 will have experienced six operations. Customers between R1 and R2 will have experienced two. See Figure 6. Current as a percent of minimum trip for the 200-A recloser Figure 6. Recloser 2's C curve operation, shown in green 4 S&C Information Bulletin 461-50 . TripSaver® II Cutout-Mounted Recloser Faulted Circuit with Sequence Coordination In the example shown in Figure 7, R1 is set with a Sequence Coordination TCC curve slightly slower than the R1 recloser's C curve for easy visibility on the graph. R1 will switch to this curve upon sensing a current-level drop from the fault level to a level below pickup. Figure 7 shows the A and C curves and the sequence coordination curve setting. Note: It's perfectly acceptable to set the Sequence Coordination TCC curve to the same settings as the slow C curve. Figure 8 shows the two reclosers fast and slow sequences and R1's Sequence Coordination TCC curve (in yellow) on the same graph. Current as a percent of minimum trip for the 200-A recloser Figure 7. Recloser 1's A and C curves and the Sequence Coordination TCC curve (in yellow) Current as a percent of minimum trip for the 200-A recloser Figure 8. Curves for Reclosers 1 and 2, including the Sequence Coordination TCC curve (in yellow). . S&C Information Bulletin 461-50 5 TripSaver® II Cutout-Mounted Recloser Now, when a fault occurs downstream of R2, shown as the dashed line in Figure 9, R2's fast A curve will operate on TCC0 and TCC1. Customers downstream of R2 will have experienced two operations. On the first operation on TCC0 of the downline recloser (R2), R1 sees the current level drop from a fault level to a level below pickup and switches to its slower Sequence Coordination TCC curve. As the fault persists, R2's slower C curve will operate to lockout. Customers downstream will have experienced four operations. Customers between R1 and R2 will have experienced no operations. See Figure 10. Current as a percent of minimum trip for the 200-A recloser Figure 9. Recloser 2 operating on an A curve setting and Recloser 1 switching to the Sequence Coordination TCC curve (in yellow) without operating. Current as a percent of minimum trip for the 200-A recloser Figure 10. Recloser 2 operating to lockout, as shown in the Sequence Coordination TCC curve (in yellow) 6 S&C Information Bulletin 461-50 .Adobe PDF Library 17.0 Adobe InDesign 20.0 (Macintosh)